Most power-generating stations include numerous large pieces of equipment, through which a substantial quantity of superheated steam is delivered to a steam turbine and then returned to a steam generator. Power-generating stations generally operate continuously as a source of electrical energy in a given geographic area. Periodically, the entire station (or a part of the station) must be shut down in order to perform repairs and preventive maintenance on the equipment. In view of the large size of the equipment and in view of the fact that it is desirable to get the station back on line at the earliest possible time with a minimum of shutdown time, it has been found desirable to move machine tools into a power-generating station to perform the necessary maintenance and repairs on the equipment. One of the problems which is encountered in making necessary maintenance and repairs on equipment is that it is often necessary to reface flange couplings and the like in order to have a perfectly flat face, so that seals may be effected when the equipment is reassembled after a period of work on the equipment. Heretofore, there has been no equipment available which is portable and may be used to cut a flat surface on a piece of equipment. All too often, hand-grinding wheels were used to remove scale, rust and other materials from a flange, which resulted in an uneven surface. It is a principal object of this invention to provide a portable facing machine which may be transported to a power-generating station to cut a flat face on a large piece of equipment for flanges having a diameter of six feet and larger.